Structural analysis of Gigartina pistillata carrageenans (Gigartinaceae, Rhodophyta)

The chemical structure of carrageenans produced by the gametophytic and tet rasporophytic life cycle phases of Gigartina pistillata has been determined by permethylation analysis, IR and C-13 NMR spectroscopies. The chemistry of the galactans varies according to the biological phases of the plant, th e gametophytic alga produces heterogeneous kappa-iota type carrageenan cont aining minor amounts of v-carrabiose. The tetrasporophytic alga synthesizes a complex sulfated galactan composed of lambda-, xi-, pi -carrabioses and sulfated carrabioses containing 3-linked galactopyranose 2,6-disulfate. (C) 2001 Elsevier Science Ltd. All rights reserved.